2.7V TO 5.5V VCC CPVDD FB+ MAX9788 CLASS G OUTPUT STAGE CHARGE PUMP

Transcription

1 9-7; Rev 3; 5/8 EVALUATI KIT AVAILABLE 4VP-P, Class G Ceramic Speaker Driver General Description The features a mono Class G power amplifier with an integrated inverting charge-pump power supply specifically designed to drive the high capacitance of a ceramic loudspeaker. The charge pump can supply greater than 7mA of peak output current at 5.5VDC, guaranteeing an output of 4V P-P. The maximizes battery life by offering highperformance efficiency. Maxim s proprietary Class G output stage provides efficiency levels greater than Class AB devices without the EMI penalties commonly associated with Class D amplifiers. The is ideally suited to deliver the high output-voltage swing required to drive ceramic/piezoelectric speakers. The device utilizes fully differential inputs and outputs, comprehensive click-and-pop suppression, shutdown control, and soft-start circuitry. The is fully specified over the -4 C to +85 C extended temperature range and is available in small lead-free 28-pin TQFN (4mm x 4mm) or 2-bump WLP (2mm x 2.5mm) packages. Applications Features Integrated Charge-Pump Power Supply No Inductor Required 4V P-P Voltage Swing into Piezoelectric Speaker 2.7V to 5.5V Single-Supply Operation Clickless/Popless Operation Small Thermally Efficient Packages 4mm x 4mm 28-Pin TQFN 2mm x 2.5mm 2-Bump WLP Ordering Information PART PIN-PACKAGE TEMP RANGE EWP+TG45 2 WLP -4 C to +85 C ETI+ 28 TQFN-EP* -4 C to +85 C +Denotes a lead-free package. T = Tape and reel. G45 indicates protective die coating. *EP = Exposed pad. Cell Phones Smartphones MP3 Players Personal Media Players Handheld Gaming Consoles Notebook Computers Typical Application Circuit/Functional Diagram and Pin Configurations appear at end of data sheet. Simplified Block Diagram 2.7V TO 5.5V VCC CPVDD FB+ C IN R IN+ R FB+ IN+ IN- + - CLASS G OUTPUT STAGE OUT+ OUT- C IN R IN- R FB- FB- CHARGE PUMP GND CPGND Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim Direct at , or visit Maxim s website at

2 ABSOLUTE MAXIMUM RATINGS (Voltages with respect to GND.) V CC, CPV DD...-.3V to +6V PV SS,...-6V to +.3V CPGND...-.3V to +.3V OUT+, OUT-...( -.3V) to (V CC +.3V) IN+, IN-, FB+, FB V to (V CC +.3V) CN...(PV SS -.3V) to (CPGND +.3V) CP...(CPGND -.3V) to (CPV DD +.3V) FS, SHDN...-.3V to (V CC +.3V) Continuous Current Into/Out of OUT+, OUT-, V CC, GND,...8mA CPV DD, CPGND, CP, CN, PV SS...8mA Any Other Pin...2mA Continuous Power Dissipation (T A = +7 C) 2-Bump WLP (derate.3mw/ C above +7 C) (Note )...827mW 28-Pin TQFN (derate 2.8mW/ C above +7 C)...667mW Operating Temperature Range...-4 C to +85 C Storage Temperature Range C to +5 C Lead Temperature (soldering, s)...+3 C Bump Temperature (soldering) Reflow C Note : Package thermal resistances were obtained using the method described in JEDEC specification JESD5-7, using a fourlayer board. For detailed information on package thermal considerations, see Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (V CC = V CPVDD = V SHDN = 3.6V, V GND = V CPGND = V, R IN+ = R IN- = kω, R FB+ = R FB- = kω, R FS = kω, C = 4.7µF, C2 = µf; load connected between OUT+ and OUT-, Z LOAD = Ω + µf, unless otherwise stated; T A = T MIN to T MAX, unless otherwise noted. Typical values are at T A = +25 C.) (Notes 2, 3) GENERAL PARAMETER SYMBOL CDITIS MIN TYP MAX UNITS Supply Voltage Range V CC Inferred from PSRR test V Quiescent Current I CC 8 2 ma Shutdown Current I SHDN SHDN = GND.3 5 µa Turn-On Time t Time from shutdown or power-on to full operation 5 ms Input DC Bias Voltage V BIAS IN_ inputs (Note 4) V Charge-Pump Oscillator Frequency I LOAD = ma (slow mode) f OSC I LOAD > ma (normal mode) khz SHDN Input Threshold V IH.4 (Note 5) V IL.4 V SHDN Input Leakage Current ± µa SPEAKER AMPLIFIER T A = +25 C ±3 ±5 Output Offset Voltage V OS T MIN T A T MAX ±2 mv Click-and-Pop Level V CP A-weighted, 32 samples per second Peak voltage into/out of shutdown (Notes 6, 7) -67 dbv Voltage Gain A V (Notes 4, 8) db Output Voltage V OUT f = khz, % THD+N V CC = 5V 7. V CC = 4.2V 5.9 V CC = 3.6V 5. V CC = 3.V 4.2 V RMS 2

3 ELECTRICAL CHARACTERISTICS (continued) (V CC = V CPVDD = V SHDN = 3.6V, V GND = V CPGND = V, R IN+ = R IN- = kω, R FB+ = R FB- = kω, R FS = kω, C = 4.7µF, C2 = µf; load connected between OUT+ and OUT-, Z LOAD = Ω + µf, unless otherwise stated; T A = T MIN to T MAX, unless otherwise noted. Typical values are at T A = +25 C.) (Notes 2, 3) PARAMETER SYMBOL CDITIS MIN TYP MAX UNITS Output Voltage V OUT f = khz, % THD+N, Z L = µf + Ω, no load Continuous Output Power P OUT % THD+N, f = khz, R L = 8Ω Power-Supply Rejection Ratio (Note 4) Total Harmonic Distortion Plus Noise PSRR THD+N V CC = 5V 6.5 V CC = 4.2V 5.4 V CC = 3.6V 4.7 V CC = 3.V 3.3 V CC = 5V 2.4 V CC = 4.2V.67 V CC = 3.6V.25 V CC = 3.V.8 V CC = 2.7V to 5.5V f = 27Hz, 2mV P-P ripple 77 f = khz, 2mV P-P ripple 77 f = 2kHz, 2mV P-P ripple 58 Z L = µf + Ω, V OUT = khz /.9V RMS.2 Z L = µf + Ω, V OUT = khz / 4.V RMS.8 Signal-to-Noise Ratio SNR V OUT = 5.V RMS, A-weighted 8 db Common-Mode Rejection Ratio CMRR f IN = khz (Note 9) 68 db Dynamic Range DR A-weighted (Note ) V CC = 5V 6 V CC = 3.6V 5 V RMS W db % db Note 2: All devices are % production tested at room temperature. All temperature limits are guaranteed by design. Note 3: Testing performed with resistive and capacitive loads to simulate an actual ceramic/piezoelectric speaker load, Z L = µf + Ω. Note 4: Input DC bias voltage determines the maximum voltage swing of the input signal. Inputing a signal with a peak voltage of greater than the input DC bias voltage results in clipping. Note 5:.8V logic compatible. Note 6: Amplifier/inputs AC-coupled to GND. Note 7: Testing performed at room temperature with Ω resistive load in series with µf capacitive load connected across the BTL output for speaker amplifier. Mode transitions are controlled by SHDN. V CP is the peak output transient expressed in dbv. Note 8: Voltage gain is defined as: [V OUT+ - V OUT- ] / [V IN+ - V IN- ]. Note 9: PV SS is forced to -3.6V to simulate boosted rail. Note : Dynamic range is calculated by measuring the RMS voltage difference between a -6dBFS output signal and the noise floor, then adding 6dB. Full scale is defined as the output signal needed to achieve % THD+N. R IN_ and R FB_ have.5% tolerance. The Class G output stage has 2dB of gain. Any gain or attenuation at the input stage will add to or subtract from the gain of the Class G output. 3

4 Typical Operating Characteristics (V CC = V CPVDD = V SHDN = 3.6V, V GND = V CPGND = V, R IN+ = R IN- = kω, R FB+ = R FB- = kω, R FS = kω, C = 4.7µF, C2 = µf, Z L = µf + Ω; load terminated between OUT+ and OUT-, unless otherwise stated; T A = T MIN to T MAX, unless otherwise noted. Typical values are at T A = +25 C.) (Notes, 2) THD+N (%). TOTAL HARMIC DISTORTI PLUS NOISE vs. FREQUENCY V OUT = 3V RMS V CC = 2.7V toc THD+N (%). TOTAL HARMIC DISTORTI PLUS NOISE vs. FREQUENCY V OUT = 4V RMS V CC = 3.6V toc2 THD+N (%). TOTAL HARMIC DISTORTI PLUS NOISE vs. FREQUENCY V OUT = 5.9V RMS V CC = 5V toc3. V OUT =.25V RMS. V OUT =.9V RMS. V OUT = 3V RMS. k k k. k k k. k k k TOTAL HARMIC DISTORTI PLUS NOISE vs. OUTPUT VOLTAGE V CC = 2.7V f IN = khz toc4 TOTAL HARMIC DISTORTI PLUS NOISE vs. OUTPUT VOLTAGE V CC = 3.6V f IN = khz toc5 TOTAL HARMIC DISTORTI PLUS NOISE vs. OUTPUT VOLTAGE V CC = 5V f IN = khz toc6 THD+N (%). f IN = khz THD+N (%). f IN = khz THD+N (%). f IN = khz.... f IN = 2Hz f IN = 2Hz f IN = 2Hz PSRR (db) POWER-SUPPLY REJECTI RATIO vs. FREQUENCY V RIPPLE = 2mV P-P -9 k k k toc7 POWER CSUMPTI (mw) POWER CSUMPTI vs. OUTPUT VOLTAGE V CC = 2.7V f IN = khz % THD+N toc8 POWER CSUMPTI (mw) POWER CSUMPTI vs. OUTPUT VOLTAGE V CC = 3.6V f IN = khz % THD+N toc9 4

5 Typical Operating Characteristics (continued) (V CC = V CPVDD = V SHDN = 3.6V, V GND = V CPGND = V, R IN+ = R IN- = kω, R FB+ = R FB- = kω, R FS = kω, C = 4.7µF, C2 = µf, Z L = µf + Ω; load terminated between OUT+ and OUT-, unless otherwise stated; T A = T MIN to T MAX, unless otherwise noted. Typical values are at T A = +25 C.) (Notes, 2) POWER CSUMPTI (mw) POWER CSUMPTI vs. OUTPUT VOLTAGE V CC = 5V 5 f IN = khz % THD+N OUT+ 5V/div OUT- 5V/div OUT+ - OUT- V/div toc SHDN 5V/div OUT+ - OUT- 5mV/div CLASS G OUTPUT WAVEFORM 2μs/div toc3 % THD+N STARTUP WAVEFORM ms/div toc SUPPLY CURRENT (ma) SHDN 5V/div OUT+ - OUT- 5mV/div SUPPLY CURRENT vs. SUPPLY VOLTAGE SHUTDOWN WAVEFORM ms/div SUPPLY VOLTAGE (V) toc4 toc2 SHUTDOWN CURRENT (μa) SHUTDOWN CURRENT vs. SUPPLY VOLTAGE SUPPLY VOLTAGE (V) toc5 SUPPLY CURRENT (ma) SUPPLY CURRENT vs. OUTPUT VOLTAGE V CC = 5V f IN = khz toc6 5

6 Typical Operating Characteristics (continued) (V CC = V CPVDD = V SHDN = 3.6V, V GND = V CPGND = V, R IN+ = R IN- = kω, R FB+ = R FB- = kω, R FS = kω, C = 4.7µF, C2 = µf, Z L = µf + Ω; load terminated between OUT+ and OUT-, unless otherwise stated; T A = T MIN to T MAX, unless otherwise noted. Typical values are at T A = +25 C.) (Notes, 2) OUTPUT AMPLITUDE (VRMS) OUTPUT AMPLITUDE vs. FREQUENCY V CC = 3.6V V CC = 2.7V V CC = 5V k k k toc7 GAIN (db) FREQUENCY RESPSE 2 V OUT = 2VRMS k k k toc8 WLP PACKAGE THERMAL DISSIPATI (W) WLP PACKAGE THERMAL DISSIPATI AND OUTPUT POWER vs. TEMPERATURE OUTPUT POWER PACKAGE THERMAL DISSIPATI toc9 V CC = 5V TEMPERATURE ( C) Pin Description OUTPUT POWER (W) TQFN PIN WLP NAME B2 SHDN Shutdown 2, 5, 6, 8,, 7, 9, 23, 25, 28 FUNCTI No Connection. No internal connection. 3 A2 CP Charge-Pump Flying Capacitor, Positive Terminal. Connect a 4.7µF capacitor between CP and CN. 4 A3 CPV DD Charge-Pump Positive Supply 7 A4 FB- Negative Amplifier Feedback 9 A5 IN- Negative Amplifier Input B5 IN+ Positive Amplifier Input 2 B4 FB+ Positive Amplifier Feedback 3 C5 FS Charge-Pump Frequency Set. Connect a kω resistor from FS to GND to set the charge-pump switching frequency. 4, 22 D, D5 V CC Supply Voltage. Bypass with a µf capacitor to GND. 5, 2 C2, C4 Amplifier Negative Power Supply. Connect to PV SS. 6 D4 OUT- Negative Amplifier Output 8 D3 GND Ground 2 D2 OUT+ Positive Amplifier Output Charge-Pump Output. Connect a µf capacitor between PV 24 C PV SS and SS CPGND. 26 B CN Charge-Pump Flying Capacitor, Negative Terminal. Connect a 4.7µF capacitor between CN and CP. 27 A CPGND Charge-Pump Ground. Connect to GND. EP EP Exposed Pad. Connect the TQFN EP to GND. 6

7 Detailed Description The Class G power amplifier with inverting charge pump is the latest in linear amplifier technology. The Class G output stage offers improved performance over a Class AB amplifier while increasing efficiency to extend battery life. The integrated inverting charge pump generates a negative supply capable of delivering greater than 7mA. The Class G output stage and the inverting charge pump allow the to deliver a 4V P-P voltage swing, up to two times greater than a traditional singlesupply linear amplifier. Class G Operation The Class G amplifier is a linear amplifier that operates within a low (V CC to GND) and high (V CC to ) supply range. Figure illustrates the transition from the low to high supply range. For small signals, the device operates within the lower (V CC to GND) supply range. In this range, the operation of the device is identical to a traditional single-supply Class AB amplifier where: I LOAD = I N As the output signal increases so a wider supply is needed, the device begins its transition to the higher supply range (V CC to ) for the large signals. To ensure a seamless transition between the low and high supply ranges, both of the lower transistors are on so that: I LOAD = I N + I N2 As the output signal continues to increase, the transition to the high supply is complete. The device then operates in the higher supply range, where the operation of the device is identical to a traditional dual-supply Class AB amplifier where: I LOAD = I N2 During operation, the output common-mode voltage of the adjusts dynamically as the device transitions between supply ranges. Utilizing a Class G output stage with an inverting charge pump allows the to realize a 2V P-P output swing with a 5V supply. BTL CLASS G SUPPLY TRANSITI V CC V CC V CC I P I P I P P Z L P Z L P Z L I N N I N N N OFF N2 OFF I N2 N2 I N2 N2 LOW SUPPLY RANGE OPERATI I P = I N SUPPLY TRANSITI I P = I N + I N2 HIGH SUPPLY RANGE OPERATI I P = I N2 Figure. Class G Supply Transition 7

8 Inverting Charge Pump The features an integrated charge pump with an inverted supply rail that can supply greater than 7mA over the positive 2.7V to 5.5V supply range. In the case of the, the charge pump generates the negative supply rail (PV SS ) needed to create the higher supply range, which allows the output of the device to operate over a greater dynamic range as the battery supply collapses over time. Shutdown Mode The has a shutdown mode that reduces power consumption and extends battery life. Driving SHDN low places the in a low-power (.3µA) shutdown mode. Connect SHDN to V CC for normal operation. Click-and-Pop Suppression The Class G amplifier features Maxim s comprehensive, industry-leading click-and-pop suppression. During startup, the click-and-pop suppression circuitry eliminates any audible transient sources internal to the device. Applications Information Differential Input Amplifier The features a differential input configuration, making the device compatible with many CODECs, and offering improved noise immunity over a single-ended input amplifier. In devices such as PCs, noisy digital signals can be picked up by the amplifier s input traces. The signals appear at the amplifier s inputs as common-mode noise. A differential input amplifier amplifies the difference of the two inputs and signals common to both inputs are canceled out. When configured for differential inputs, the voltage gain of the is set by: RFB AV = db _ 2log 4 R ( ) IN_ where A V is the desired voltage gain in db. R IN+ should be equal to R IN-, and R FB+ should be equal to R FB-. The Class G output stage has a fixed gain of 4V/V (2dB). Any gain or attenuation set by the external input stage resistors will add to or subtract from this fixed gain. See Figure 2. In differential input configurations, the common-mode rejection ratio (CMRR) is primarily limited by the external resistor and capacitor matching. Ideally, to achieve the highest possible CMRR, the following external components should be selected where: and C IN+ R IN+ R IN- R FB+ R FB- Figure 2. Gain Setting RFB+ RIN+ RFB RIN = CIN+ = CIN FB+ IN+ C IN- IN- FB- + - CLASS G OUTPUT STAGE 8

9 Driving a Ceramic Speaker Applications that require thin cases, such as today s mobile phones, demand that external components have a small form factor. Dynamic loudspeakers that use a cone and voice coil typically cannot conform to the height requirements. The option for these applications is to use a ceramic/piezoelectric loudspeaker. Ceramic speakers are much more capacitive than a conventional loudspeaker. Typical capacitance values for such a speaker can be greater than µf. High peak-topeak voltage drive is required to achieve acceptable sound pressure levels. The high output voltage requirement coupled with the capacitive nature of the speaker demand that the amplifier supply much more current at high frequencies than at lower frequencies. Above khz, the typical speaker impedance can be less than 6Ω. The is ideal for driving a capacitive ceramic speaker. The high charge-pump current limit allows for a flat frequency response out to 2kHz while maintaining high output voltage swings. See the Frequency Response graph in the Typical Operating Characteristics. Figure 3 shows a typical circuit for driving a ceramic speaker. A Ω series resistance is recommended between the amplifier output and the ceramic speaker load to ensure the output of the amplifier sees some fixed resistance at high frequencies when the speaker is essentially an electrical short. Component Selection Input-Coupling Capacitor The AC-coupling capacitors (C IN_ ) and input resistors (R IN_ ) form highpass filters that remove any DC bias from an input signal (see the Functional Diagram/ Typical Operating Circuit). C IN_ blocks DC voltages from the amplifier input. The -3dB point of the highpass filter, assuming zero source impedance due to the input signal source, is given by: f 3dB = Hz 2π RIN_ CIN_ ( ) Ceramic speakers generally perform best at frequencies greater than khz. Low frequencies can deflect the piezoelectric speaker element so that high frequencies cannot be properly reproduced. This can cause distortion in the speaker s usable frequency band. Select a C IN so the f -3dB closely matches the low frequency response of the ceramic speaker. Use capacitors with low-voltage coefficient dielectrics. Aluminum electrolytic, tantalum, or film dielectric capacitors are good choices for AC-coupling capacitors. Capacitors with high-voltage coefficients, such as ceramics (non- CG dielectrics), can result in increased distortion at low frequencies. Charge-Pump Capacitor Selection Use capacitors with an ESR less than 5mΩ for optimum performance. Low-ESR ceramic capacitors minimize the output resistance of the charge pump. For best performance over the extended temperature range, select capacitors with an X7R dielectric. CLASS G OUTPUT STAGE OUT+ OUT- RL Flying Capacitor (C) The value of the flying capacitor (C) affects the load regulation and output resistance of the charge pump. A C value that is too small degrades the device s ability to provide sufficient current drive. Increasing the value of C improves load regulation and reduces the chargepump output resistance to an extent. Above µf, the onresistance of the switches and the ESR of C and C2 dominate. A 4.7µF capacitor is recommended. Figure 3. Driving a Ceramic Speaker 9

10 Hold Capacitor (C2) The output capacitor value and ESR directly affect the ripple at PV SS. Increasing C2 reduces output ripple. Likewise, decreasing the ESR of C2 reduces both ripple and output resistance. A µf capacitor is recommended. Charge-Pump Frequency Set Resistor (R FS ) The charge pump operates in two modes. When the charge pump is loaded below ma, it operates in a slow mode where the oscillation frequency is reduced to /4 of its normal operating frequency. Once loaded, the charge-pump oscillation frequency returns to normal operation. In applications where the design may be sensitive to the operating charge-pump oscillation frequency, the value of the external resistor R FS can be changed to adjust the charge-pump oscillation frequency shown in Figure 4. A kω resistor is recommended. Ceramic Speaker Impedance Characteristics A µf capacitor is a good model for the ceramic speaker as it best approximates the impedance of a ceramic speaker over the audio band. When selecting a capacitor to simulate a ceramic speaker, the voltage rating or the capacitor must be equal to or higher than the expected output voltage swing. See Figure 5. Series Load Resistor The capacitive nature of the ceramic speaker results in very low impedances at high frequencies. To prevent the ceramic speaker from shorting the output at high frequencies, a series load resistor must be used. The output load resistor and the ceramic speaker create a lowpass filter. To set the rolloff frequency of the output filter, the approximate capacitance of the speaker must be known. This information can be obtained from bench testing or from the ceramic speaker manufacturer. A series load resistor greater than Ω is recommended. Set the lowpass filter cutoff frequency with the following equation: flp = Hz 2π RL CSPEAKER ( ) WLP Applications Information For the latest application details on WLP construction, dimensions, tape carrier information, PCB techniques, bump-pad layout, and recommended reflow temperature profile, as well as the latest information on reliability testing results, go to the Maxim website at for the application note, UCSP A Wafer- Level Chip-Scale Package. CHARGE-PUMP OSCILLATI FREQUENCY (khz) CHARGE-PUMP OSCILLATI FREQUENCY vs. R FS I LOAD > ma R FS (kω) fig4 IMPEDANCE (Ω) M k k k IMPEDANCE vs. FREQUENCY CERAMIC SPEAKER μf CAPACITOR... fig5 Figure 4. Charge-Pump Oscillation Frequency vs. R FS Figure 5. Ceramic Speaker and Capacitor Impedance

11 SHDN CTROL SIGNAL Typical Application Circuit/Functional Diagram 2kΩ SHDN (B2) V CC 4, 22 (D, D5) V DD CPV DD 4 (A3).μF * C IN.47μF R IN+ kω R FB+ kω 2 (B4) (B5) 9 (A5) FB+ IN+ IN- + - CLASS G OUTPUT STAGE OUT+ OUT- 2 (D2) 6 (D4) R L Ω C IN.47μF R IN- kω R FB- kω 7 (A4) FB- GND CHARGE PUMP CPGND CN CP PV SS FS 3 (C5) R FS kω 8 (D3) 27 (A) 26 (B) 3 (A2) 24 (C) 5, 2 (C2, C4) ( ) WLP PACKAGE DEVICE SHOWN WITH A V = 2dB *SYSTEM-LEVEL REQUIREMENT TYPICALLY μf C 4.7μF C2 μf

12 TOP VIEW + 28 CPGND 27 CN PVSS VCC 22 TOP VIEW (BUMP SIDE DOWN) Pin Configurations SHDN OUT+ A CPGND CP CPV DD IN- FB- CP 3 9 B CPV DD GND C CN SHDN FB+ IN+ 6 7 EP* 6 5 FB- OUT- D PV SS FS V CC OUT+ GND OUT- V CC IN- IN+ FB+ FS VCC WLP THIN QFN *EXPOSED PAD. Package Information For the latest package outline information and land patterns, go to PACKAGE TYPE PACKAGE CODE DOCUMENT NO. 2 WLP W22A TQFN T PROCESS: BiCMOS Chip Information 2

13 REVISI NUMBER REVISI DATE DESCRIPTI Revision History PAGES CHANGED 2/6 Initial release /7 2 2/8 Include tape and reel note, edit Absolute Maximum Ratings, update TQFN package outline Replaced USCP with WLP package throughout data sheet including new WLP package outline, added new TOC 9 and Note, 2,3, 4, 2, 3, 6,,, 2, 5, 6 3 5/8 Updated Typical Application Circuit and corrected stylistic errors 6, Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated Products, 2 San Gabriel Drive, Sunnyvale, CA Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc.